Field of the Disclosure
This disclosure relates generally to walkers for moving structures over the ground. Exemplary structures are oil and gas rigs.
Description of Related Art
This section is intended to introduce various aspects of the art, which may be associated with the present disclosure. This discussion is believed to assist in providing a framework to facilitate a better understanding of particular aspects of the present disclosure. Accordingly, it should be understood that this section should be read in this light, and not necessarily as admissions of prior art.
Structures such as oil and gas rigs may be disassembled, transported, and then reassembled on an adjacent well. Often if disassembly is to be avoided, and the next hole is on the same location, the rig can be pulled onto the next hole by using winch trucks or bulldozers. This can be a time consuming, dangerous, and haphazard process. Walkers can eliminate the need for disassembly and reassembly by using hydraulics to lift and move a rig to its new drilling location.
Certain walkers use mechanisms called “stomp pads.” These mechanical units operate independently from each other and are attached to the bottom of the structure being moved. The stomp pads are designed to carry the weight of the structure while advancing it in a particular direction. Because the surface area of each of these stomp pads is relatively small, high pressures are placed on the ground which can lead to ground cracking and sinkage, potentially destabilizing the entire structure.
Individual pads that operate independently from one another have other problems. One problem can occur when the structure needs to be moved in a different direction. Current “stomp pad” designs require manual adjustment of each individual stomp pad when a direction change is required. Manual adjustment can be time consuming and prone to error. Moreover, if the stomp pads are improperly aligned, high stresses may be placed on the joints of the walker and which could lead to damage of the walker or the structure itself.
In view of the aforementioned disadvantages, there is a need for an alternative walker.